Extreme pressure greases



ing one head or another to the generator, a pluralityofcontrol elements'at the heads. for controlling the radio frequency switches, means including ashaftfor varying the voltage output of the radio frequency generator, a motor for moving said shaft, a plurality of discs frictionally secured to the shaft, a toothed stop element secured to said shaft, a pawl for engaging and locking said stop element, cam rollers engaging said discs, said discs being recessed to receive the rollers to mark a desired stopping point depending on the adjustment of the disc relative to the staft andcorresponding to the desired radio frequency voltage for the corresponding head,- and detent means to hold out and make inoperative the rollers, each of the aforesaid control elements serving to close'a radio frequency switch, and to start the motorin order to rotate the aforesaid shaft in forward direction, and to release and make operative a cam roller which on entering the cam depression changes the position of a switch and thereby stopsthe motor and operates the locking pawl.

l4. Pillheati-ng apparatus for use with-a plurality of molding presses using a plurality'of different size pills, said apparatus comprising a heating head foreach press, a radio frequency generator, radio frequency switches for connecting one head or another to the generator, a plurality of control elements at the heads for controlling relay circuits, means including a shaft for varying the voltage output of the radio frequency generator, a motor for moving said shaft, a plurality of discs frictionally secured to the shaft, a toothed stop element secured to said shaft, a pawl for engaging and locking said stop element, cam rollers engaging said discs, said discs being recessed to receive the rollers to mark a desired stopping point depending on the adjustment of the disc relative to the shaft and corresponding to the desired radio frequency voltage for the corresponding head, detent means to hold out and make inoperative the rollers, and a timing clock for timing the heating of the pills, each of the aforesaid relay circuits serving to close a radio frequency switch, and to start the motor in order to rotate the shaft in forward direction, and to start the timing clock, and to release and make operative a cam roller which on entering the cam depression changes the position of a switch and thereby stops the motor and operates the locking pawl, running out of said timing clock serving to oppositely change said relay circuit and to thereby release the pawl, to reverse the motor, to restore the roller to the detent means, and to open the radio frequency switch.

15. Pill heating apparatus for use with a plurality of molding presses using a plurality of different size pills, said apparatus comprising a heating head for each press, a radio frequency generator, radio frequency switches for connecting one head or another to the generator, a plurality of control elements at the heads for controlling the radio frequency switches, a low frequency power supply for the radio frequency generator including a variable transformer or variac for-varying the voltage output of the radio frequency generator, a motor for driving the variac shaft through reduction gearing, a plurality of discs frictionally secured to the variac shaft, a toothed stop element secured to said shaft, a pawl for engaging and locking said stop element, cam rollers engaging said discs, said discs being recessed to receive the rollers to mark a desired stopping point depending on the adjustment of the disc relative to the shaft and corresponding to the desired radio frequency voltage for the corresponding head, and detent means to hold out and make inoperative the rollers, each of the aforesaid control elements serving to close a radio frequency switch, and to start the motor in order to rotate the variac inforwarddirection, and to release and make operative a cam roller which on entering the cam depression changes the position of a switch and thereby stops the motor and operates the locking pawl.

16. Pill heating apparatus for use with a plurality of molding presses using a plurality of different size pills, said apparatus comprising a heating head for each press, a radio frequency generator, radio frequency switches for connecting onehead or another to the generator, a plurality of control elements at the heads for controlling relay circuits, alow frequency power supply for the radio frequency generator including a variablev transformer or variac for varying the voltage output of the radio frequency generator, a motor: for driving the variac shaft through reduction gearing, a plurality of discs friction lly secured to the variac shaft, a toothed stop element secured to said shaft, a pawl for engaging and locking said stop element, cam rollers engaging said discs, said discs being recessed to receive the rollers to mark a desired stopping point depending on the adjustment of the disc relative to the shaft and corresponding to the desired radio frequency voltage for the corresponding head, detent means to hold out and make inoperative the rollers, and a timing clock for timing the heating of the pills, each of the aforesaid relay circuits serving to close a radio frequency switch, and to start the motor in order to rotate the variac in forward direction, and to start the timing clock, and to release a cam roller which on entering the cam depression changes the position of a switch and thereby stops the motor and operates the locking pawl, running out of said timing clock serving to oppositely change said relay circuit and to thereby release the pawl, re-

- verse the motor, restore the roller to the detent means, and open the radio frequency switch.

17. A remotely controlled mechanism for moving a variac or like control device from zero to any of several different desired positions, said mechanism including a motor to drive the variac shaft, a switch to control the operation of the motor, a toothed wheel positively secured to said shaft, a pawl for engaging the teeth of said wheel to stop and lock the shaft, a plurality of cams frictionally rotatable on said shaft, each of said cams having a stop depression and being independently rotatively adjustable on the shaft to a desired position, a plurality of cam rollers for engaging said cams, a detent for normally holding said cam rollers in inoperative position, means for selecting and releasing one of said cam rollers from said detent to operative position, said cam roller on entering the stop depression of its associated cam serving to change the positionof said motor switch and thereby serving to deenergize the motor and to actuate said locking pawl, and additional means to facilitate adjusting the desired stop positions of the cams, said means including a position locking means for so positively holding the selected cam roller in its stop depression that it is not forced out by attempted rotation of the cam, means for making said locking pawl inoperative, and a handle on said variac shaft for forcibly rotating the shaft and with it all but one of the cams, the excepted cam being locked against rotation by the aforesaid cam roller and locking means.

18. Pill heating apparatus for use with a plurality of molding presses using a plurality of difierent size pills, said apparatus comprising a heating head for each press, a single radio frequency generator, switches for connecting one head or another to the generator, a plurality of control elements, voltage control means for varying the voltage output of the generator, a motor for driving said voltage control means, a plurality of difi'erent independently selectable stop means for stopping movement of said voltage control means at a desired point, means to independently adjust the stop position of each of said stop means, a timing clock for timing the heating of the pills, each of the aforesaid control elements serving to close one of the switches and to start the motor in order to move the voltage control means in forward direction and to start the timing clock and to make one of the stop means operative, said stop means stopping the motor at the desired voltage output, and running out of said timing clock serving to reverse the motor and open the switch.

GORDON B. SAYRE.

16 REFERENCES CITED I The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 1,513,681 Ward Oct. 28, 1924 2,036,516 Golanduoni Apr. 7, 1936 2,085,442 Newell June 29, 1937 2,094,777 Ellinger Oct. 5, 1937 2,102,070 Harris Dec. 14, 1937 2,153,865 Gersch Apr. 11, 1939 2,234,911 Davis Mar. 11, 1941 2,251,277 Hart, Jr., et al Aug. 5, 1941 2,275,284 Carlson Mar. 3, 1942 2,280,766 Bronaugh Apr. 21, 1942 2,293,851 Rogers Aug. 25, 1942 2,334,724 Paessler Nov. 23, 1943 2,367,763 Elliott Jan. 23, 1945 2,391,470 May Dec. 25, 1945 2,401,277 Stratton May 28, 1946 2,401,991 Walton et al June 11, 1946 2,403,800 Hoyler July 9, 1946 2,415,799 Riefel et a1 Feb. 11, 1947 2,419,307 Zottu Apr. 22, 1947 2,490,619 Clark Dec. 6, 1949 2,506,814

Sayre May 9, 1950 Patented Jan. 2 2, 1952 UNITED STATES PATENT OFFICE 2,583,394 EXTREME PRESSURE GREASES John E. Schott, NewYork, and Eldon L. Armstrong, Garden City, N. Y., assignors to Socony- Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application September 20, 1950,

SerialNo. 185,913

1 This is a continuation-in-part of our co-pending application, Serial Number 79,518, filed March 3, 1949 for High Temperature Extreme Pressure Greases, now abandoned.

This invention relates to an improved method for preparing improved lubricating grease compositions useful for high pressure service. It is directed to improved methods of preparing greases based upon soaps of the alkaline earth metals, and particularly directed to an improved method for preparing a lime-base grease containing a lead soap, and metal salts of low molecular weight mono-basic fatty acids. I

The greases prepared by the method of this invention are well adapted for extreme pressure service where high unit loads are encountered,

for example in the lubrication of roller bearings" in steel mills. A lime base grease made according to this procedure is also adapted for use at temperatures going up to about 300-325 F. which is substantially higher than those at which ordinary calcium base greases may be employed.

An object of this invention is the provision of 9 Claims. (Cl. 252-36) 2 vantages not found in prior art methods. Since this method permits the addition of acetic acid at room temperature to the kettle batch prior to saponification, the partial loss thereof by vaporian economical and efficient method for making improved greases which utilize for bases the soaps of alkaline earth metals, e. g., calcium, barium, magnesium and strontium, and which contain extreme pressure ingredients and improving amounts of metal salts of low molecular weight monobasic fatty acids. invention is the provision of an efficient, rapid and economical process for making calcium-lead soap greases. Another object is the provision of an improved lubricant for extreme pressure service containing calcium and lead soaps, These apparent from the following discussion.

An object of this and other objects of this invention will become Heretofore, in'pr'eparing lead greases containing the soaps of lead and another metal, it has been customary to first prepare a grease containing the other metal and then to add thereto a separately prepared lead soap or soaps followed byextended heating of the mixture to accomplish proper distribution of the lead soaps therein. For'example, in the case of an alkali base soap, a sodium base grease is first prepared by methods well known to the art and a lead soap,.

for example lead oleate prepared by reacting litharge with oleic acid, is added and gradually worked into the sodium base grease. It has now been found that a very good lime base grease may i be prepared by mixing together at atmospheric.

temperature the saponifiable material with litharge and lime and a mono-basic fatty acid such as acetic acid followed by heating under pressure to effect simultaneous saponification of allthe This is followed by a dehydration materials. step. This method has been found not only to provide a superior more stable grease but results in substantial manufacturing economies and adzation which has been, encountered in prior grease manufacturing methods is avoided. Also,

EXAMPLE I Pounds Tallow a 625 Glycerine 110 Candelilla wax Oleic acid 330 Lime flour Ca(OH)z 2'70 Acetic acid 180 Water 150 Paraffin oil (300" at F. Saybolt) 1,300

Litharge slurry dispersed in 35 gallons of 300" parafi'in oil wt. of litharge 1'73 After the pressure kettle has been charged with all of the above materials at about atmospheric temperature, the mixture is heated slowly while mixing to about 300 F. at which temperature substantially complete saponification is accomplished. It is desirable to maintain the kettle under pressure during the saponification step. A pressure of 60 pounds gauge has been found to be satisfactory. The saponification is completed in about two hours after which the contents of the pressure kettle are blown" over into an open kettle and about 194 gallons of 100" at 100 F. paraffin oil are added while paddling the mixture. Then while continuing the mixing by paddles, steam is turned into the kettle jacket and the mixture is heated gradually to about 250 F. at atmospheric pressure after which it is rapidly heated to about 300 F. By this procedure dehydration is effected to a degree sufficient to insure high temperature stability of the final grease. The mixture is maintained at 300-310 F.

for one and one half hours and then it is cut back slowly with about 44 gallons of 300" at 100 F. S. U. V. paraffin oil followed by about 100 gallons of '200" at 210 F. Mid-Continent oil. The latter oil is added only as fast'as'it will flow from the small bung opening of a standard 50 gallon steel 3 barrel. Then, the mixture is further out back by adding more rapidly an additional 250 gallons of the 200" at 2 F. S. .U. V. Mid-Continentpoil. During the cut-back operation, steam is maintained in the jacket. The steam is finally turned off with the mixture at about 290-300 F. and 500 pounds of sulfurized fatty oil are added while 11 mixing. (The sulfurized fatty oil is prepared by heating a fatty oil such as lardoil or sperm' oil with about 10 percent of its weight ofzsuliur for 7 about 3 hours at a temperature above about 200 F.) Finally up to 100 gallons of 300'. at 100 F.

were added to the mixture.

F. to eirect dehydration. The dehydration step required about 5 hours -About 90 gallons of 100" at 100% F: STU. V.- paraffin oilia'nd 75 gallons of 200" at 210 F. S. U. V. Mid-Continent oil Then about '70 pounds of lime flour, Ca(OH)2 mixed in 35 gallonsof 100 -at 100 F. S. U. V. paraflin oil were added. The kettle contents were mixed for a half hour after which a lead oleate concentrate was-added. "The-lead oleate concentrate consisted of=about60-percent of lead oleate and 40 ,percent of 100" at100 F. S. U. V. parafiin oil.

S. U. V. parafiin oil is added to adjust the-batch :to.""

the desired penetration grade. Cold water is then admitted to the jacket and the grease is-cooled to about 180 F. for filling into packages. In preparing-this grease the total material compounded together breaks down as follows:

r Percent weight Tallow The total time consumed in preparation of this grease is about 10-12 hours. The resulting grease is of excellent consistency and is stable under service at very high unit -load pressures. Moreover, due to the presence of calcium acetate, the grease has remarkable high temperature characteristics as indicated by arr A. S. T. M. drop point higher than about 400 F. For purposes of comparison the grease prepared 'in the manner. hereindescribed hereinabove will be referred'to after as Process A- grease;

The advantagesofthe above processover'those of the prior art and the improvement in the properties of the resulting grease as compared with.

prior; art alkali base-lead soap. greaseslare very marked; -In-order to reduce thenumber of variables andto emphasize the importance of the procedure of effecting simultaneous saponification of fats or fatty acids with lime and litharge together. the process of; this invention may be best contrasted'with a process wherein.a;lime.baselead soap grease is prepared following theme-nu facturing procedure; employed by the prior art in;

preparing leadg feases containing a lead soap addition to another metal; -Using the. manuz-v facturing process procedure of the prior art, a pressure kettle was chargedas follows:

' E AM I Tallow pounds 625 Candelilla wax do 180 Li-me flour (Ca(O-H)2) do 240 Water do 165 Paraflin til soo'f at F. s. U. V. gallons 1'76 Saponification. was effected at about 300 F. and 60 pounds per-square inch in about two hours. The kettle contents were then blown over to an open kettle-and gallons of 300'. at 100 F. S. U. V. paraffin oil was added while mixing. -The mixture was cooled to about F.

and 110 pounds of glycerine and pounds of acetic acid were added. ,The kettle contents were mixed by paddling forabout 45 minutes.

afterrwhich the mixture was heated to about 300 The-lead 'oleatconcentrate was prepared separately'by reacting litharge with oleic acid in the presence of mineral oil. About 330 gallons of 200" at 210 S. U. V. Mid-Continent oil and 90 gallons oflOO" at 100 F. S. U. V. paraffin oil were then addedian'd the mixture was heated to about 300-320 .F. and'mixed for about 4 hours to effectdistribution of the lead oleate in the mixture. Then 500pounds of suliurized fatty oil were added to the mixture followed by'mixing for another half hour. The 'grease'wa's then cooled for packaging. The required time con sumed in preparing this grease was about 22 hours- .The grease'from' this latter process will be referred to hereinafter as Process B grease.

Applicants are-not aware of a prior art lead containing grease inw'hich metal acetates have been employed. Metal acetates have been employed in certain other typesofgreases' and in such instances it has been the practiceto follow one'iof two procedures. 1 In the first method the metal acetates have been separately formed and then' added bymixing into the formed grease."

Poor. uniformity: ofv mixing often results from thisproce'dure. The second procedure has been to' add acetic acid to theba'tch after the saponificationstep' andprior to the dehydration step. The batch is "hot at this stage of the process and a loss by'vaporization of part of the added acetic acid occurs. This results in inaccurate control of the; amount 'of metal acetates finally formed. It will be 'appare'nt'that applicants method avoids the "disadvantages of the prior art methods.

The greases prepared "bythe above described I methods were tested for storage stability, shear stability and TimkenO."K. load ratings. The storage stability oi the greases was determined by running worked and unworked penetrations on samples of thefgrease-before and after storagefemploying thef standardA. S. T. M. procedure outlined-in A. ;S. T. M; test D-217-4 1T and using-a1l5'0-gram cone The shear test was I conducted by subjecting a grease sample to a 1 continuous shear condition for a period of three and one half hours after which A.S. T. M. penetrations'were run on thegrease; The shear testingsystem consists of "a grease reservoir of greater than-l0 pounds of grease capacity. The reservoir is piped to a piston pump which draws the grease-fromthereservoir. The high pressure sideofthe pump is piped to a relief valve set for maintaining about 2000 pounds per square inch gauge pressure? The grease is forced through the reli'ef'valve and then passes through about 32 feet of'one' inch pipe'backto the reservoir where it is again pick'edup by the pump for recirculation. -After three and one half hours circulatioir the grease is'removed from the shear tester 'and evaluated for worked and unworked 5 penetrations. 'The-values so obtained are comparedarwithrthose of the original grease before the shear test. --The spread in values represents an approximate measure of what might be GX- pected when the greases are subjected in use to high shearing'pressures. The load test is one originally developed by the Timken Roller Bearing Company of Canton, Ohio, for testing the load'carryingcapacity of lubricants. This test is discussed in Klemgards Lubricating Greases, 1937 edition, page 828 and the apparatus is described by E. Wooler, in Society of Automotive Engineers' Journal, volume 28, pages 54-55, J anuary 1931. signed for testing liquid oils but by addition of suitable feeding appliances which feed grease on the test pieces, the apparatus has been rendered useful for testing greases. 'A description of its use for testing greases is given in the Journal of the Institution of Petroleum, volume 26, Number 200, pages 273-283, June 1940.

The greases prepared by Processes A and B described hereinabove are compared in the table.

Table Grease Process A Process B Storage Stability- Original Penetration, ASTM 77 F.:

Timken O. K. Load-Pounds Shear Stability Tests- For 3%. hours at 2,000 pounds per squareinch gau ge. Worked Penetration ASTM 77 F. 400

It will be noted from the table that the grease prepared by the method of this invention is superior to the one prepared using prior art processes procedure with respect to storage stability, shear stability and load rating without bearing failure. Moreover, the method of this invention permits a reduction in manufacturing time using the same grease kettles from 22 hours by prior art procedure to lib-12 hours by the procedure of this invention, thereby doubling the capacity of the grease manufacturing plant. The method of this invention eliminates the necessity of preparing the lead soap separately and thereby eliminates the separate apparatus heretofore required for that step. The method of this invention also permits the introduction I of the totallime requirement in the initial kettle charge thereby eliminating the necessity for subsequent lime addition to the partically manufactured grease.

The process above described is also useful in preparing greases based upon the soaps or other alkaline earth metals, such as barium, magnesium and strontium. v

In this case a barium base grease containing leadsoaps and barium acetate was prepared. The formulation was as follows:

EXAMPLE III Ingredient: Percent by weight Acidless tallow 7.0 Olefic acid 3.6 Barium hydroxide (dry powder, 95%

B a(OI- I )z) Glycerine Ace c a -1 g"? Lith lu in i fiuliu i ed fa ty il 0% 4.0 Mineral oil (100" s. U. v. 100" F.) 37.1 Mine'ral oil (block 011, 200" S. U. V.

The apparatus was originally de- The above ingredients were compounded together using the same procedure as outlined in Example I, above. The resulting grease was of good consistency, stable in service under high unit pressures, and capable of use at reasonably high temperatures.

Its properties were:

Timken O. K. load. pounds 40 A. S. T. M. drop point F. 23'] Storage stability:

Original penetration, A. S. T. M.,

Unworked 315 Worked 340 Penetration after storage, A. S. T. M.,

After 12 days:

Unworked 280 Worked 353 After 16 days:

Unworked 280 Worked 345 Shear stability test:

3 /2 hours at 2000 pounds per square inch gauge Worked penetration, A. S. T. M.,

Similarly, competent greases may be prepared utilizing the soaps of magnesium and strontium.

It will, of course, be realized that various modifications which will readily appear to those skilled in the are may be made in the procedure outlined hereinabove without departure from the spirit and scope of this invention. Moreover, certain of the constituents mentioned may be eliminated or replaced by substitutes and the various proportions may be changed within limits depending upon the desired characteristics of the final grease. In general, the following ranges, limits and variations in the procedure are intended to be within the scope of this invention.

(1) The tall'ow and/or candelilla wax may be replaced by other suitable saponifiable materials such as lard oil, hog fat, high molecular weight organic cuts such as stearic and oleic acids, rosin and related products, beeswax, sperm oil, degras, etc. The molecular weight of these saponifiable materials should in general be greater than about 200. The saponifiable materials added should be less than about 30 percent by weight of the total material going into the grease composition.

(2) The non-corrosive sulfurized fatty oil may be prepared by methods other than that outlined in Example I. Suitable sulfurized fatty oils may be prepared by heating sulfur in varying proportions ranging up to about ten to fifteen percent by weight of the oil with sperm oil, corn oil, lard oil, cottonseed oil and the like by procedure well known to the art. The amount of sulfurized oil added to the grease composition may be controlled, in case a grease not containing sulphur in corrosive amounts is desired, to provide a grease in which the sulfur compound content of these sulfur compounds in the grease is important in that they improve its load bearing characteristics.

(3) The amount of lead added in producing the grease measured as PbO should be broadly within the range 0.5 to 5.0 percent of the total materials added and preferably within the range 1 to 2.0 percent by weight thereof. In the case 

1. A METHOD OF PRODUCING A LUBRICATING COMPOSITION COMPRISING, MIXING TOGETHER WITH A MINERAL OIL BASIC COMPOUND OF LEAD AND OF A METAL SELECTED FROM THE GROUP CONSISTING OF CALCIUM, BARIUM, MAGNESIUM, AND STRONTIUM, WITH LESS THAN THEIR EQUIVALENT OF HIGH MOLECULAR WEIGHT SAPONIFIABLE MATERIAL AND WITH A SMALL PROPORTION OF A MONO-BASIC FATTY ACID HAVING LESS THAN 4 CARBON ATOMS SUFFICIENT IN AMOUNT TO SUBSTANTIALLY NEUTRALIZE THE EXCESS BASIC METAL COMPOUNDS, THE AMOUNT OF SAID SAPONIFIABLE MATERIAL BEING SUFFICIENT TO NEUTRALIZE A MAJOR FRACTION BUT SUBSTANTIALLY LESS THAN ALL OF SAID BASIC COMPOUNDS AND THE BASIC COMPOUNDS OF LEAD AND OF SOAPFORMING METAL BOTH BEING PRESENT IN SUBSTANTIAL AMOUNTS, HEATING THE MIXTURE UNDER PRESSURE WHILE MIXING TO EFFECT ALL THE SAPONIFICATION SIMULTANEOUSLY, THEREAFTER RELEASING THE PRESSURE AND HEATING THE MATERIAL AT SUBSTANTIALLY ATMOSPHERIC PRESSURE TO EFFECT SUBSTANTIAL DEHYDRATION, ADDING A MINOR PROPORTION OF A NON-CORROSIVE SULFURIZED FATTY OIL TO THE MIXTURE AND FINALLY CUTTING BACK THE MIXTURE WITH ADDITIONAL MINERAL OIL TO THE DESIRED CONSISTENCY. 